1. Field of the Invention
The present invention relates to a molded resin complex constituting a cartridge attachable/detachable to a body of an electrophotographic image forming apparatus that adopts an electrophotographic system such as a laser printer and a copier, and a method of producing the molded resin complex. Specifically, the present invention relates to a molded resin complex in which resin molded products having low compatibility with each other are engaged so as to be separable using irradiation with laser light, and a method of producing the molded resin complex.
Herein, the electrophotographic image forming apparatus forms an image on a recording medium using an electrophotographic image forming system. Examples of the electrophotographic image forming apparatus include an electrophotographic copier, an electrophotographic printer (e.g., a laser beam printer, an LED printer, etc.), a facsimile apparatus, and a word processor.
2. Description of the Related Art
Conventionally, in an image forming apparatus using an electrophotographic image forming process, a process cartridge system is adopted. In the process cartridge system, a cartridge in which an electrophotographic photosensitive member, process means acting on the electrophotographic photosensitive member, a developing device, etc. are integrated with one another, can be attached/detached to an image forming apparatus body. According to the process cartridge system, a user can perform maintenance of an apparatus without relying upon a serviceman, so the operability can be enhanced remarkably. Thus, the process cartridge system is used widely in an image forming apparatus.
In the process cartridge, a developer container (toner container) containing a developer (toner) is connected to a developing container holding a developer carrying member (developer roller), a developer regulating member (developing blade), and so forth. It is proposed that an opening of the toner container for supplying toner to the developing container is sealed with a sealing member (toner seal) so that toner does not flow to the developing container until the commencement of use. A user pulls a sealing handle (pull-tab) attached to the process cartridge at the commencement of use to remove the toner seal fixed to the sealing handle, and then, attaches the process cartridge to the image forming apparatus body. The sealing handle is engaged with the toner container, the developing container, a bearing member or a side cover of the process cartridge so that the sealing handle does not come off easily due to vibrations or shocks during transportation or the like.
As the sealing handle, one has been known which is made of a material having low compatibility with the toner container, the developing container, the bearing member, or the side cover, and is integrally molded so as to be separable using a two-color molding method (JP-A-2003-241495).
The two-color molding method of engaging two resin molded products so as to be separable, as described in Japanese Patent Application Laid-Open No. 2003-241495, is a method of providing bonding force owing to the molding contraction of resin, and has the following problems.
(1) A flow path for a resin to be injected later is required to be formed by moving a mold piece which is used for forming part of a resin molded product to be molded first, which restricts the shape of an engagement portion.
(2) The bonding force (stress) is weakened due to a change in environmental temperature, with the result that the resin molded products may separate. In order to address such a problem, if an under-cut portion (portion having a shape preventing pull-out) is formed in the engagement portion, determining the mold pulling direction, which further restricts the shape of the engagement portion.
(3) The structure of the mold and the resin injection flow path become complicated, which increases mold costs.
(4) A molding machine exclusive to two-color molding is necessary.
On the other hand, as a method of engaging two resin molded products so as to be separable, a method of mechanically producing under-cuts such as snap-fit and thermal caulking can also be conceived. However, this method has the following problems.
(1) In a case of using a material (glass, etc.) having high elasticity in the snap-fit, the material itself is not deformed, so that the engagement portion may be deformed and damaged.
(2) It is necessary to form unevenness in consideration of the mold pulling direction in the snap-fit and thermal caulking, which restricts the mold structure.
(3) It is necessary to melt and cool the resin integrated in the thermal caulking, which takes a long time for engagement and entails assembly costs.
Accordingly, an object of the present invention is to reduce restrictions on a product design, a mold, and production facilities (molding machine) in the case of engaging two resin molded products so as to be separable, to reduce production costs, and further, to prevent the external appearance of the resulting molded resin complex and cartridge from being impaired.
The foregoing objectives can be achieved by the invention described below.